1. Field
An electrolyte for a rechargeable lithium battery and a rechargeable lithium battery including the same are disclosed.
2. Description of the Related Technology
Rechargeable lithium batteries capable of being repeatedly charged and discharged has a high voltage and a high energy density and excellent storage performance and operation performance at a low temperature and thus, are widely used as a power source for portable electronic devices.
Accordingly, rechargeable lithium batteries have been researched as being large-sized and applied to an electric vehicle or a domestic electricity storage device. However, rechargeable lithium batteries may be internally short-cut and even destroyed or exploded when they meet abnormal conditions such as overcharge and the like due to impurities therein or various reasons.
Accordingly, an electrolyte including a flame-retardant additive or an ionic liquid as an assistant solvent has been suggested to prevent these abnormal battery problems. However, the electrolyte has high stability but high viscosity and may deteriorate efficiency characteristic and decrease cycle-life characteristics of the rechargeable lithium battery.
Although the flame-retardant additive may have a stable electrochemical window, it is easily coordinated with lithium in the electrolyte and oxidized or reduction-decomposed on the interface which results in and the formation of a film and accordingly, increase interface resistance during the operation of the rechargeable lithium battery for a long period and deteriorate its cycle-life characteristics.